1. Field of the Invention
The present invention relates to a power generation control device for controlling a power generation state of a vehicle generator mounted on a vehicle such as a passenger car or a truck.
2. Description of Related Art
There is known a configuration in which a two-way communication is performed between a voltage control device included in a vehicle generator and an engine control device as disclosed, for example, in U.S. Pat. No. 6,567,476. As disclosed in this document, the voltage control device of the vehicle generator includes a communication circuit having a voltage comparator serving as a communication receiver and a switching transistor serving as a communication driver which are both connected to a communication terminal of the voltage control device. The voltage control device can perform a two-way data transmission and reception with the engine control device through a communication wire connected to the communication terminal.
However, the conventional voltage control device as disclosed in this document has a problem in that the communication receiver thereof may be caused to malfunction if electrical noise goes into the communication circuit through the communication wire and the communication terminal. Such electrical noise includes ESD (Electric Static Discharge), CI noise, and RI noise. Accordingly, it has been desired to improve the EMC (ElectroMagnetic Compatibility) of such a communication circuit performing a low-speed two-way data transmission with the engine control device by suppressing the electrical noise.